Medical records of patients with advanced non-small cell lung cancer (NSCLC) were retrospectively reviewed to examine the prognostic impact of nutritional status on survival. Age, sex, body mass index (BMI), Eastern Cooperative Oncology Group Performance Status (ECOG-PS), histologic tumor type, pulmonary comorbidities, white blood cell (WBC) count, C-reactive protein (CRP) level, and prognostic nutritional index (PNI) were assessed. Overall survival was calculated using Kaplan-Meier analysis and compared using log-rank testing. Univariate and multivariate Cox regression model analyses were used to evaluate prognostic impact. Of the 183 enrolled patients, 166 had stage IV NSCLC; 70 had ECOG-PS scores of 2; and 129 had undergone prior anticancer therapy. Age ≥ 65 years, male sex, smoking, BMI < 21 kg/m2, ECOG-PS score of 2, WBC count > 11,000 cells/μL, CRP level > 1.0 mg/dL, and PNI ≤46.1 were associated with poor overall survival. Multivariate analysis revealed that BMI ≥ 21 kg/m2 (hazard ratio [HR], 0.64) and PNI > 46.1 (HR, 0.65) were associated with prolonged survival, while age ≥ 65 years (HR, 1.48) and CRP level > 1.0 mg/dL (HR, 1.82) were associated with poor survival. In conclusion, BMI and PNI, as indicators of nutritional status, were significant independent prognostic factors of survival.